intersection_update() in Python to find common elements in n arrays

In this article, we will learn about the iintersection_update() in Python to find out common elements in n arrays.

The problem is that we are given an array containing lists, find all common elements in given arrays?

Algorithm

1.Initializingres with the first list inside the array
2.Iterating through the array containing lists
3.Updating the res list by applying intersection_update() function to check the common elements.
4.Finally returning the list and display the output by the help of the print statement.

Now let’s take a look at its implementation

Example

def commonEle(arr):

# initialize res with set(arr[0])
res = set(arr[0])

# new value will get updated each time function is executed
for curr in arr[1:]: # slicing
   res.intersection_update(curr)
return list(res)

# Driver code
if __name__ == "__main__":
   nest_list=[['t','u','o','r','i','a','l'], ['p','o','i','n','t'], ['t','u','o','r','i','a','l'],       ['p','y','t','h','o','n']]
   out = commonEle(nest_list)
if len(out) > 0:
   print (out)
else:
   print ('No Common Elements')

Output

['o', 't']

Conclusion

In this article, we learned about the iintersection_update() in Python to find common elements in n arrays and its implementation.